Not applicable.
Steel aluminum, tin or other metals are typically rolled upon a mandrel as a final phase of production. In the steel industry, these mandrels typically have a diameter of 24 or 20 inches, while in the aluminum industry that diameter typically is 16, 20, or 24 inches. The coils, are quite heavy, for example, steel coils generally weighing 60,000 up to 80,000 pounds. To transport or maneuver the coils about the mill and following their delivery to customers, cranes such as overhead cranes having a generally L-shaped or C-shaped engaging implement or a truck with a boom are employed. Typically, the engaging implement incorporates a tong or tongue which slides inside the center region of the coil and engages it for lifting. As is apparent, with the weight at hand, without some protection, the inner layers of the coil as well as the outer edges generally would be damaged. Being highly conscientious with respect to the yield of metal purchased, customers require that such damage be avoided. As a consequence, at the production mill or processor, the multi-layer coils are prepared for crane handling and shipment by the placement of flanged protectors against each coil side which are structured to protect both the edges of the metal and the internal layers of the sheet metal. Generally with this placement procedure, two mill laborers hold the coil protectors in place and they are strapped in place, or, a somewhat elaborate wrapping machine employing a shuttle will wrap both coil and the manually retained protectors with a paper or shrink wrap covering.
Currently utilized coil protectors are, for the most part, fabricated from plastic, and in view of the rigorous environment in which they are used, see only minimal reuse. While plastic recycling procedures have been promulgated, the cost of the protective devices is sought to be controlled through resort to minimizing their weight, i.e., material cost, while maintaining their capability for assuring metal coil integrity. Coil protector cost also is impacted by the cost of their shipment to the coil forming facilities. The protectors necessarily are relatively large and bulksome. To achieve a cost control over their transportation it is desirable that they be stackable prior to packaging and shipping. Such a stacking capability improves the efficiency of both their trucking to coil production facilities and their practical storage when at the site of the user. Practical coil protector stacking should provide a structurally stable column or stack, of no less than about 50 or 60 devices, preferably more, having a height extending within highway transportation regulatory authority mandated limitations.
In the course of producing metal coils, some variations in their open internal diametric extent may be expected. Tolerance variations also will be experienced in the production of plastic coil protectors, which is usually carried out utilizing injection molding procedures. Thus, the design of the protectors must be such as to accommodate tolerance-based variations in the internal diameters of the coils themselves, as well as practical or unavoidable variations experienced in the dimensions of the plastic protectors themselves. Accordingly, coil protector designs must be capable of assuring a proper union with the protected metal coil, as well as assuring that the protectors remain stackable for packaging and shipping purposes.
The present invention is addressed to polymeric protectors as are employed with sheet metal coils. Configured with a flange and sleeve integrally conjoined at a ridge portion, the protectors of the invention will accommodate for tolerancing variations both with respect to their own molded fabrication, as well as those variations encountered in the formation of sheet metal coils. One embodiment provides for the incorporation, inter alia, of relief openings which extend through the ridge portion of their structures. With such an arrangement the circumferential extent of the ridge portions of the protectors may be strained in compression by a wedging or scrunching action asserted upon the sleeve as they may be manually urged into engagement with the internally disposed surface of a coil core. When so inserted, the sleeves are retained within the core without further manual support by integrally formed resilient fingers extending from the sleeves. The noted relief openings serve an additional purpose of contributing to a reduction in the plastic material utilized to mold the protectors. When that material reduction is combined with the corresponding material reductions achieved with a pattern of holes formed in the flange as well as stacking features, an overall cost improving material savings of about 30% is achieved.
The protectors of the invention further enjoy an important stackability attribute which contributes to the economy of their usage. Substantial improvement in the numbers which may be stacked to form a vertically secure protector assemblage is realized with an initial embodiment through the incorporation of groupings of a three component stacking feature. Those components include a stacking tab formed with the sleeve, a stacking tab access opening surmounting a finger configured to provide a stacking receiver surface, and a stacking opening dimensioned to receive a finger structure in stacking relationship. In general, three such groupings are arranged symmetrically about the axis of the flange, the components within each group being mutually spaced apart, for example, in a regular manner.
The corresponding stacking method for this embodiment provides for a positioning of the edge of the sleeve of an initial protector upon a lifting surface such as a pallet or skid. Then, the sleeve of a next protector is inserted within the lifting surface supported sleeve of the initial protector in a manner wherein its stacking tabs engage the receiver surfaces of the fingers of the initial protector. As this occurs, the fingers of this next protector are positioned within the stacking openings of the initial protector.
This stacking procedure is reiterated with a plurality of protectors, each next protector being angularly shifted about the flange axis with respect to the last stacked in position to evolve a somewhat spirally arranged stack vertical assemblage of protectors. For protectors configured for use with sheet steel coils, about 100 may be stacked within a vertical stack height of about 7xc2xd feet. Following such stacking, the stack of protectors is compressively retained within a protective wrap in conjunction with the lifting surface. No substantial protector-to-protector slippage is encountered within the stack such that the stack retains an integrity of verticality throughout its subsequent shipping and storage.
In another embodiment, an annular flange is integrally conjoined with a tapered insertion sleeve having stacking openings incorporating stacking offset openings extending radially into the flange. A stacking tongue is incorporated at the lower end of the stacking opening in combination with a radially outwardly disposed and axially aligned stacking socket. The socket incorporates a receiving chamber configured for receiving the stacking tongue of another protector in stacking relationship. To avoid flange warpage, the protectors may also incorporate a radially outwardly disposed angular reinforcement ridge.
The stacking procedure for this latter embodiment provides for the positioning of the sleeve edge of an initial protector upon a working surface. Then, the sleeve of the next protector is positioned through the upwardly disposed ridge portion of the initial protector and insertion sleeve in a manner wherein the sockets of the next protector pass through the offset openings and the receiving chamber thereof slidably engages the corresponding tongue of the next lower protector.
Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter. The invention, accordingly, comprises the apparatus and method possessing the construction, combination of elements, arrangement of parts and steps which are exemplified in the following detailed description.
For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings.